Automatic cleaners adapted to travel through a swimming pool for cleaning debris from the water and/or wall surface are well known in the art. Some such cleaners are configured to be powered by a water flow supplied from a positive pressure source, e.g., an electric pump. The supplied water flow typically drives a propulsion subsystem configured to propel the cleaner body along a travel path through the pool with the subsystem functioning primarily to move the cleaner body in a first direction (i.e., forward state) in the pool and to occasionally redirect the cleaner body (i.e., backup/redirect state) in a different, or second, direction. By so redirecting the cleaner body, the risk that it will get trapped behind an obstruction in the pool is minimized.
U.S. Pat. No. 6,365,039 (incorporated herein by reference) describes various positive pressure cleaner embodiments which incorporate a propulsion subsystem for moving the cleaner body along its travel path. The propulsion subsystems described therein generally include a valve assembly carried by the cleaner body which, in a forward state, directs a supplied water flow along a first interior path to produce forces on the body for moving it in a first direction or, in a backup/redirect state, along a second interior path to produce forces on the body to redirect it in a second direction different from the first direction. The valve assembly embodiments described in U.S. Pat. No. 6,365,039 employ a valve actuator for controlling a valve element mounted for reciprocal linear movement between first and second positions for respectively directing the supplied water flow along either the first or second interior path. When the actuator is activated, it moves the valve element from a default position to an actuated position to open one of said interior paths. When the actuator is deactivated, a spring in the actuator restores the valve element to its default position to open the other of said interior paths.